Cardio-vascular drugs

Question 1

Why is aspirin contra-indicated in children? (1)

Answer 1

Aspirin in children is associated with Reye’s syndrome.

Question 2

What is Reye’s syndrome? (2)
What is the main age of children affected? (1)
What are the 2 main causes acknowledged? (2)

Answer 2

Severe, progressive encephalopathy affecting children (peak at age 2) that is accompanied by fatty infiltration of the liver, kidneys and pancreas.
Aspirin use and viral cause.

Question 3

Name 3 side effects of thiazide diuretics. (3)

Answer 3

Increased serum cholesterol
Hypokalaemia
Hyperuricaemia (may precipitate gout)
Impairment of glucose tolerance

Question 4

Name 3 common side effects of beta blockers. (3)

Answer 4

Bradycardia, bronchospasm, cold extremities, fatigue and weakness.
Exacerbation of intermittent claudication, nightmares and hallucinations

Question 5

Name 3 beta blockers that are more cardio-selective. (3)

Answer 5

Atenolol, Bisoprolol, Nebivolol, Acebutolol, Metoprolol

Question 6

name 3 side effects associated with treatment with ACE inhibitors. (3)

Answer 6

First-dose hypertension, dry cough, proteinuria, rash, leucopenia.

Question 7

Why are ACE inhibitors contraindicated in renal artery stenosis? (2)

Answer 7

AT2 is powerful vasoconstrictor,
In renal artery stenosis, constriction of the efferent arteriole is vital to maintain GFR and blood flow to the kidney.
Loss of AT2 leads to vasodilation
Vasodilation means less blood flow to the kidney

Question 8

Why do ARBs not cause dry cough caused by ACEi? (1)

Answer 8

Bradykinin is broken down by ACE, ACE inhibitors can therefore prevent this and levels can build up causing a cough.

Question 9

Name 2 dihydropyridine calcium channel blockers. (2)

Answer 9

Felodipine, amlodipine, nifedipine

Question 10

Which 2 calcium channel blockers are contraindicated in heart failure? (2)
Which is the most negatively ionotropic? (1)

Answer 10

Diltiazem and verapamil

Verapamil is highly negative ionotropic and decreases cardiac output and heart rate, diltiazem is less so.

Question 11

Which calcium channel blocker is particularly contraindicated with beta blockers? (1)

Answer 11

Verapamil.

Diltiazem is used in caution.

Question 12

What is labetalol’s second classification? (1)

Answer 12

Beta blocker and also has some vasodilator properties.

Question 13

Which calcium channel blocker can be used to treat raynauds syndrome? (1)

Answer 13

Nifedipine

Question 14

Which calcium channel blocker is licensed for use in SVT’s? (1)

Answer 14

Verapamil

Question 15

Name 2 side effects of calcium channel blockers. (2)

Answer 15

Bradycardia, headaches, flushing, fluid retention (oedema) and cardiac conduction defects (V&D only)

Question 16

What is the mechanism of action of adenosine? (2)

Name the main indication. (1)

Answer 16

Enhances flow of potassium out of myocardial cells causing hyperpolarisation and stabilisation of cell membranes. It has potent effects on the SA node and slows conduction through the AV node.
Atrioventricular junction tachycardias eg Wolff-Parkinson-White

Question 17

Name 3 important things regarding the administration of adenosine. (3)

Answer 17

Rapid IV injection
Into central or large peripheral vein
Cardiac monitoring and resuscitation available
CI: asthma, heart block (unless pacemaker fitted)

Question 18

What is the Vaughan Williams classification? (4)

Answer 18

Classification of anti-arrhythmics.
Class I: Sodium channel blockers (lidocaine, flecainide)
Class II: Beta blockers
Class III: Potassium channel blockers (amiodarone)
Class IV: Calcium channel blockers (D&V)

Question 19

What is the mechanism of action of amiodarone? (2)

Answer 19

Potassium channel antagonist.. slows repolarisation and so prolongs refractory period.

Question 20

What are the indications of amiodarone? (2)

Answer 20

In CPR, when pulseless VT and VF are unresponsive to other interventions.
Treatment of arrhythmias (SVT and VT, AF) especially when other therapies are not tolerated or ineffective.

Question 21

How is oral amiodarone initiated? (2)

Answer 21

Week 1: 200mg TDS
Week 2: 200mg BD
Week 3 onwards : 200mg OD

Question 22

What monitoring is required for amiodarone? (2)

Answer 22

TFTs before and 6 monthly

LFTs before and 6 monthly

Question 23

Name 4 side effects of amiodarone therapy. (4)

Answer 23

Hypothyroidism
hyperthyroidism 
Liver toxicity
Corneal microdeposits (reversible)
Phototoxic skin reactions (total sunblock cream)
Slate-grey skin pigmentation
Pneumonitis
Peripheral neuropathy

Question 24

Bill was on amiodarone for control of his arrhythmia, however, it was stopped 1 month ago and he is now starting warfarin therapy.
What is the worry? (1)

Answer 24

Amiodarone has a very long half life and can remain in the body for several weeks. It interacts with warfarin.

Question 25

What is the mechanism of action of digoxin? (2)

Answer 25

Blocks AV conduction Reduces heart rate by enhancing vagal nerve activity and inhibiting sympathetic nerve activity Positively ionotropic by increasing intracellular calcium levels.

Question 26

What monitoring should be undertaken before starting digoxin therapy? (1)

Answer 26

U&E's for renal function. If reduced renal function, dose should be reduced.

Question 27

Name 4 side effects of digoxin? (4) | What electrolyte imbalance can predispose to toxicity? (1)

Answer 27

Nausea, vomiting, diarrhoea, blurred or yellow/green vision. Toxicity: Ventricular arrhythmias or bradyarrhythmias. Hypokalaemia (and renal failure)

Question 28

How are beta blockers beneficial in heart failure? (2)

Answer 28

Decrease heart rate, reduce force on contraction and decrease blood pressure => reduce myocardial oxygen demand and more time for coronary perfusion.

Question 29

What is the mechanism of action of nitrates? (2)

Answer 29

Increase cGMP in vascular smooth muscle cells => decrease in intracellular calcium levels => smooth muscle relaxation of veins and arteries => reduce venous return and workload of LV

Question 30

Why are nitrates used sub lingually preferentially? (1)

Answer 30

S/L route avoids first pass metabolism | Also in case of tablets can be removed once effect has been achieved to avoid unwanted effects.

Question 31

What valvular problem is a contraindication for calcium channel blockers? (1)

Answer 31

Aortic stenosis

Question 32

What drug classification is nicorandil? (1)

Answer 32

Potassium channel activator (it indirectly causes calcium channel blockade and arterial dilation.

Question 33

What is the mechanism of aspirin? (2)

Answer 33

Irreversible inhibition of cyclo-oxyegnase, reducing platelet production of thromboxane A2.

Question 34

What is the mechanism of dipyridamole? (2)

Answer 34

Inhibits phosphodiesterase-mediated breakdown of cAMP (more cAMP) so prevents platelet activation.

Question 35

What is the mechanism of action of clopidogrel? (2)

Answer 35

Blocks platelet aggregation and prolongs platelet survival by inhibiting the binding of ADP to it's platelet receptor.